Objective: To determine the degree of placental transfer of rosiglitazone in early human pregnancy.
Design: Prospective observational study.
Setting: University teaching hospital.
Patient(s): Thirty-one women undergoing surgical termination of pregnancy between 8 and 12 weeks' gestation.
Intervention(s): Each woman was given two doses of rosiglitazone (4 mg) before the procedure.
Main outcome measure(s): Rosiglitazone concentration in fetal tissue and coelomic and amniotic fluids.
Result(s): The mean maternal serum rosiglitazone concentration was 110.3 +/- 47.9 ng/mL. Rosiglitazone was detectable in 19 fetal samples (61.3%). The mean fetal tissue concentration was 52.7 +/- 26.3 ng/g. Rosiglitazone was more likely to be detected in fetal tissue if the gestation at termination was 10 weeks or more compared with earlier gestation. Coelomic fluid was obtained in 22 cases, and rosiglitazone was detected in 13 samples (59.1%). The mean concentration was 22.8 +/- 7.0 ng/mL. Rosiglitazone was detectable in only two of the 31 amniotic fluid samples, with concentrations of 10.3 and 12.6 ng/mL.
Conclusion(s): The risk of placental transfer of rosiglitazone is much higher at or after 10 weeks of gestation. Absence of detectable rosiglitazone in amniotic fluid despite its presence in fetal tissue suggests that fetuses may have the ability to metabolize rosiglitazone, and little parent drug was excreted unchanged in urine.